Near Real-Time Global Ocean Prediction System (Apr 2007 - October 2008 ) |
| System Description |
| The system is configured for the global ocean with HYCOM 2.2 as the dynamical model. Computations are carried out on a mercator grid between 78 oS and 47 oN (1/12o equatorial resolution). A bipolar patch is used for regions north of 47 oN. The horizontal dimensions of the global grid are 4500 x 3298 grid points resulting in ~7 km spacing on average. There are 32 vertical layers (see blkdat.input). Bathymetry is derived from a quality controled NRL DBDB2 dataset. Surface forcing is from Navy Operational Global Atmospheric Prediction System (NOGAPS) and includes wind stress, wind speed, heat flux (using bulk formula), precipitation. For additional details on the model configuration such as layer reference densities time steps, advection scheme, mixing etc. see blkdat.input. |
| Data Assimilation |
| The system uses the Navy Coupled Ocean Data Assimilation (NCODA) system (Cummings, 2005; QJRMS) for data assimilation. NCODA uses the model forecast as a first guess in a multi-variate Optimal Interpolation (MVOI) scheme and assimilates available satellite altimeter observations (along track obtained via the NAVOCEANO Altimeter Data Fusion Center) satellite and in-situ Sea Surface Temperature (SST) as well as available in-situ vertical temperature and salinity profiles from XBTs, ARGO floats and moored buoys. Note: Currently the assimilation is performed from 67 S to 47 N. |
| Operational Details and Data Availablity |
| The system runs daily at 18:00 hrs and generates a 5 day hindcast and a five day forecast. The data are made available typically within a day after the model run through servers located at Center For Ocean Atmospheric Prediction Studies (COAPS), Florida State University(FSU). The HYCOM format archive files are converted to CF 1.0 compliant NetCDF files using standard HYCOM post-processing package. These files contain diagnostic output at standard Levitus depth levels for several variables including currents, temperature and salinity. These files can be accessed using any OPeDAP enabled client e.g, ferret, Matlab, NCO etc. The OPeNDAP URL are available from the HYCOM THREDDS Catalog. The HYCOM Live Access Server allows request for a number of products such as images, custom subsets of data, data access scripts etc. Individual files can also be accessed via standard anonymous FTP. |
| Information on Run Configuration, Computational Grids, Model Bathymetry and Variables |
| blkdat.input Contains model run configuration information such as time steps, advection scheme, mixing etc, vertical structure etc. |
| regional.grid Files containing the location of model grid points |
| regional.depth Files containing the model bathymetry |
| OPeNDAP.info List of model variables and metadata |
| Reference: NRL Website contains snapshots, animations forecast verification statistics and model data comparisons. |
| Disclaimer: This is a demonstration product from the HYCOM Consortium and is provided as is. HYCOM Consortium does not warrant or suggest that this data is fit for any particular purpose. Further, COAPS does not guarantee availability, service updates or timely data delivery |
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